Got my Phantom 4 Pro+. Set up Wi-Fi. Upgraded the firmware of the drone and the remote controller. Created DJI account, etc. While palying with the user interface accidentally tapped something like "log out". Since that the only thing I can get from the controller is the sign in prompt screen, while sign in fails with "missing network" error - I suppose that Wi-Fi settings are lost or the "sign in" screen is displayed before Wi-Fi activation has been done. The reason causing the sign in to fail is actually not very important in this scenario, the question is "how to get out of that sign in screen?". Is there at least a way to reset the controller to its factory settings?

Found the https://forum.dji.com/forum.php?mod=viewthread&tid=111932 topic, got the bar with some controls on the bottom of the screen. Still cannot leave the sign in prompt: the triangle symbol pops "press again to exit" prompt but pressing it again does not produce any result. Square symbol brings to a black page stating "Your recent screens appear here", where nothing seem to appear and from there I can only get back to the sign in.

Solved: noticed that the after some manipulations on the bar on the lower part of the screen, a clock with a gear symbol was shown in the upper right part of the screen and there was a gear symbol that brought me to the settings showing that Wi-Fi was turned off. Turned it on and was able to sign in, finally getting the access to the device. I believe that this sign in is implemented on a completely wrong place and in a rather wrong way. For instance, what should one do if there is no internet connection available? If this is a kind of protection from unauthorized access like traditional user credentials to access a traditional computer or smartphone - why it can only work if an Internet connection is available? Leaving aside minor questions like that I did not turned off Wi-Fi, just accidentally tapped "log out", etc.

A new challenge: the screen of the controller is now blocked by a modal prompt to link a phone number to my account, following it offers to "Enter a mainland China telephone number" to get a verification code. Do I really have to fly to China and obtain a mainland phone number there just to accomplish the registration process and be finally able to do something with the drone?
It also looks as if the complete registration by DJI is supposed to be the ultimate purpose of everyone's life, which is not necessarily true.

fansb9972bfd Posted at 2017-9-6 19:16
A new challenge: the screen of the controller is now blocked by a modal prompt to link a phone number to my account, following it offers to "Enter a mainland China telephone number" to get a verification code. Do I really have to fly to China and obtain a mainland phone number there just to accomplish the registration process and be finally able to do something with the drone?
It also looks as if the complete registration by DJI is supposed to be the ultimate purpose of everyone's life, which is not necessarily true.

Go to Settings-System Settings-Backup&Reset-Factory Data Reset,  then reset the RC, see if it works.